Retractable cleaning nozzle

ABSTRACT

A retractable cleaning nozzle for spray cleaning an interior surface of a pipe or a tank includes a nozzle housing configured to be stationary mounted in a hole of the side wall of the pipe or tank and having a front side arranged to face towards the interior of the pipe or tank and a rear side arranged to face away from the interior of the pipe or tank, an inlet port configured for receiving a cleaning fluid, and a cylindrical interior bore with a central axis defining an axial direction, wherein the interior bore is open towards the front side of the nozzle housing. The cleaning nozzle includes a first plug movably arranged in the axial direction within the bore of the nozzle housing between a retracted position and a protruding position, wherein the first plug has a sleeve-shaped body with a front wall closing a front portion of the sleeve-shaped body, wherein the front wall of the sleeve-shaped body includes a first set of spray holes configured to eject cleaning fluid substantially in the axial direction, wherein the sleeve-shaped body of the first plug includes a second set of spray holes configured to eject cleaning fluid substantially in a radial direction perpendicular to the axial direction, wherein a front surface of the first plug is substantially flush with a front surface of the nozzle housing in the retracted position of the first plug, and wherein a front portion of the first plug, including the first and second set of spay holes, protrudes beyond the front surface of the nozzle housing in the protruding position of the first plug for enabling spray cleaning of the interior surface of the pipe or tank. The cleaning nozzle includes a second plug arranged within a space defined by the sleeve-shaped body of the first plug and configured for closing a flow path from the inlet port to the first set of holes of the first plug when the first plug is located in the retracted position.

TECHNICAL FIELD

The present disclosure relates to a retractable cleaning nozzle forspray cleaning an interior surface of a pipe or a tank, as well as amethod for spray cleaning an interior surface of a pipe or a tank usinga retractable cleaning nozzle.

The retractable cleaning nozzle according to the disclosure can bemounted in the wall of a tank or a pipe that requires periodic cleaning,such as for example in the pharmaceutical industry, food processingindustry, brewery industry, chemical industry, or the like.

BACKGROUND

In the field of cleaning nozzles for spray cleaning an interior surfaceof a pipe or a tank, there is a continuous demand for furtherimprovement in terms of cleaning efficiency and high hygienic standard.

For example, document EP0295325A1 shows a retractable cleaning nozzlethat may be substantially flush with the interior surface of the tank inretracted state, while providing radially directed spray of cleaningfluid when set in a protruding state.

This type of retractable cleaning nozzles provides a high level ofhygienic standard, because the flush mounting in retracted statesefficiently reduces the space for retention of fluid product, therebyreducing risk for bacterial growth.

However, despite the activities in the field, there is still a demandfor further improved cleaning nozzle in terms of cleaning efficiencycombined with a high hygienic standard.

SUMMARY

An object of the present disclosure is to provide an improvedretractable cleaning nozzle in terms of cleaning efficiency and highhygienic standard. This object is at least partly achieved by thefeatures of the independent claims.

According to a first aspect of the present disclosure, there is provideda retractable cleaning nozzle for spray cleaning an interior surface ofa pipe or a tank. The cleaning nozzle comprising: a nozzle housingconfigured to be stationary mounted in a hole of the side wall of thepipe or tank and having a front side arranged to face towards theinterior of the pipe or tank and a rear side arranged to face away fromthe interior of the pipe or tank, an inlet port configured for receivingcleaning fluid, and a cylindrical interior bore with a central axisdefining an axial direction, wherein the interior bore is open towardsthe front side of the nozzle housing; a first plug movably arranged inthe axial direction within the bore of the nozzle housing between aretracted position and a protruding position, wherein the first plug hasa sleeve-shaped body with a front wall closing a front portion of thesleeve-shaped body, wherein the front wall of the sleeve-shaped bodyincludes a first set of spray holes configured to eject cleaning fluidsubstantially in the axial direction, wherein the sleeve-shaped body ofthe first plug includes a second set of spray holes configured to ejectcleaning fluid substantially in a radial direction perpendicular to theaxial direction, wherein a front surface of the first plug issubstantially flush with a front surface of the nozzle housing in theretracted position of the first plug, and wherein a front portion of thefirst plug, including the first and second set of spay holes, protrudesbeyond the front surface of the nozzle housing in the protrudingposition of the first plug for enabling spray cleaning of the interiorsurface of the pipe or tank; and a second plug arranged within a spacedefined by the sleeve-shaped body of the first plug and configured forclosing a flow path from the inlet port to the first set of holes of thefirst plug when the first plug is located in the retracted position.

According to a second aspect of the present disclosure, there isprovided a method for spray cleaning an interior surface of a pipe or atank using a retractable cleaning nozzle. The cleaning nozzle has anozzle housing stationary mounted in a hole of a side wall of the pipeor tank, wherein the nozzle housing has a front side facing towards theinterior of the pipe or tank and a rear side facing away from theinterior of the pipe or tank. The nozzle housing further has an inletport for receiving a cleaning liquid, a cylindrical interior bore with acentral axis defining an axial direction, a first plug movably arrangedin the axial direction within the bore and a second plug, the methodcomprising: controlling a linear actuator operatively connected to themoveable first plug for moving the first plug from the a retractedposition to a protruding position, in which a front portion of the firstplug, including a first and a second set of spay holes, protrudes intothe tank or pipe, thereby initiating ejection of cleaning fluid via thefirst set of spray holes of the first plug substantially in the axialdirection, and initiating ejection of cleaning fluid via the second setof spray holes of the first plug substantially in a radial directionperpendicular to the axial direction; and controlling the linearactuator for moving the first plug from the protruding position to theretracted position, in which a front surface of the first plug issubstantially flush with a front surface of the nozzle housing, and inwhich the second plug closes the flow path from the inlet port to thefirst set of spray holes of the first plug.

In this way, the cleaning nozzle may still be mounted substantiallyflush with the interior surface of the tank or pipe, thereby maintaininga high hygienic standard, while also providing improved cleaningefficiency due to the combined forwards and sideways spray of cleaningfluid in the protruding operating state of the nozzle.

Further advantages are achieved by implementing one or several of thefeatures of the dependent claims.

In some example embodiments, the retractable cleaning nozzle furthercomprises a first sealing arrangement for sealing the first plug to thenozzle housing, in particular for sealing an annular space between thefirst plug and the nozzle housing, and a second sealing arrangement forsealing the second plug to the first plug, in particular for sealing anannular space between the second plug and the first plug. Sealing theflow of cleaning liquid using said annular space enables use ofcost-efficient, reliable and easily replaced sealing rings.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the first sealing arrangement isarranged for sealing an annular space between a radially outer surfaceof the first plug and a radially inner surface of the nozzle housing.Sealing the flow of cleaning liquid using said annular space enables useof cost-efficient, reliable and easily replaced sealing rings.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the second sealing arrangement isarranged for sealing the second plug to the first plug in the retractedposition of the first plug only. Thereby, automatic closure and sealingof the ejection flow is accomplished by merely moving first plug fromprotruding to retracted position.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the first plug further has a centralcylindrical operating stem extending in the axial direction, and thesecond plug has a central cylindrical hole extending in the axialdirection and configured to receive the operating stem of the firstplug. The centrally arranged operating stem enables compact design andimplementation of a rotatable first plug.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the retractable cleaning nozzlefurther comprises a third sealing arrangement for sealing an annularspace between a radially inner surface of the second plug and a radiallyouter surface of the first plug. Thereby, there is no leakage along saidoperating stem.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the first sealing arrangement isarranged for sealing the first plug to the nozzle housing in theretracted position of the first plug only. Thereby, the first sealingarrangement may be located close to the front side of the first plug andthus providing a very small space for a working product in the retractedposition.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the first and second sealingarrangements, specifically the first, second and third sealingarrangements, are located substantially in same radial plane when thefirst plug is in retracted position. This may enable a good sealingperformance due to good force transfer through the seals in theretracted position.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the retractable cleaning nozzlefurther comprises a fourth sealing arrangement for sealing the firstplug to the nozzle housing in the protruding position of the first plug.Thereby, more cleaning liquid is forced to be ejected via dedicatedspray holes.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the second and fourth sealingarrangements, specifically the second, third and fourth sealingarrangements, are located substantially in same radial plane when thefirst plug is in protruding position. This may enable a good sealingperformance due to good force transfer through the seals in theprotruding position.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the first and/or second and/or thirdand/or fourth sealing arrangement is a sealing ring, in particular anO-ring. This provides a cost-efficient design.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the nozzle housing and the first andsecond plugs are made of stainless steel or the like. This provides astrong, reliable and hygienic design.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the first sealing arrangement ismounted in an annular recess in a radially outer surface of a frontportion of the sleeve-shaped body of the first plug, and the fourthsealing arrangement is mounted in an annular recess in a radially outersurface of a rear portion of the sleeve-shaped body of the first plug.Thereby, automatic closure and sealing of the ejection flow isaccomplished by merely moving first plug from protruding to retractedposition.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the essentially flat front surfaceof the first plug extends to the first sealing arrangement, in theradial direction. This ensures a very small volume for working productentering the cleaning nozzle.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the second plug includes a centralcylindrical shaft with a radially outwards extending flange at a frontend thereof, wherein a forwards facing, preferably flat, surface of theflange abuts against a corresponding rearwards faced surface of thefront wall of the first plug. This ensures a very small volume forworking product entering the cleaning nozzle.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the first set of spray holes areclosed on rear side of said spray holes by the second plug. This ensuresa very small volume for working product entering the cleaning nozzle.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the retractable cleaning nozzle isfree from a member located in front of the first set of spray holes.Thereby, the cleaning nozzle may have a flat front surface that is flushwith surrounding surface of the pipe or tank.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the second sealing arrangement ismounted in an annular recess in a radially outer surface of the flangeof the second plug, and third sealing arrangement is mounted in anannular recess in a radially inner surface of the flange of the secondplug. This may enable a good sealing performance due to good forcetransfer through the seals.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the nozzle housing as an inlet portfor receiving cleaning fluid, and the cleaning fluid is configured toflow from the inlet port to the first and second set of spray holes viaan annular passage defined by the second sealing arrangement and aradially inner surface of the sleeve-shaped portion of the first plug,in the protruding position of the first plug. Thereby, an easily sealedflow path to the first and second sets of spray holes is provided.

In some example embodiments, that may be combined with any one or moreof the above-described embodiments, the nozzle housing as an inlet portfor receiving cleaning fluid, and the cleaning fluid is configured to bestopped from being ejected by means of the first and second sealingarrangements, in the retracted position of the first plug. Thereby, aneasily sealed flow path to the first and second sets of spray holes isprovided.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the retractable cleaning nozzlefurther comprises a linear actuator operatively connected to themoveable first plug for controlling movement of the first plug betweenthe retracted position and protruding position. Thereby, accurate andreliable control of the motion of the first plug is accomplished.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the linear actuator includes astationary actuator housing, a linearly moveable actuating member and adriving member operatively connected with the actuating member, whereinthe stationary actuator housing is rigidly attached to the stationarynozzle housing, and the actuating member is operatively connected to thefirst plug for controlling movement of the moveable first plug betweenthe retracted position and protruding position. Thereby, accurate andreliable control of the motion of the first plug is accomplished.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the retractable cleaning nozzlefurther comprises a rotating mechanism arranged to cause the first plugto become angularly displaced a predetermined angle, such as for examplein the range of 5-175 degrees, specifically in the range of 20-110degrees, around its central longitudinal axis during each activationevent, which involves moving the first plug from the retracted positionto the protruding position, and back to the retracted position again.Thereby, accurate and reliable control of the rotating motion of thefirst plug is accomplished.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the rotating mechanism is arranged tocause the first plug to become angularly displaced a first predeterminedangle around its central longitudinal axis during motion of the firstplug from the retracted position to the protruding position, andarranged to cause the first plug to become angularly displaced a secondpredetermined angle around its central longitudinal axis during motionof the first plug from the protruding position to the retractedposition. Thereby, the rotating mechanism may be made more compact.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the rotating mechanism includes: atleast one radially protruding guide member rotationally connected withthe first plug and a cam member rotationally connected with thestationary nozzle housing or actuator housing, or at least one radiallyprotruding guide member rotationally connected with stationary nozzlehousing or actuator housing and a cam member rotationally connected withthe first plug; wherein the cam member has at least one cam-surfaceinclined with respect to the axial direction and configured forinteracting with the at least one radially protruding guiding member forinducing a controlled rotation of the first plug upon motion of thefirst plug from the retracted position to the protruding position, andback to the retracted position again. The use of a cam memberinteracting with guide member enables cost-efficient and reliablecombined axial and rotational motion using merely a linear actuator.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the rotating mechanism includes a setof at least two radially protruding guide members rotationally connectedwith a piston of a pneumatic linear actuator, and a cam memberrotationally secured to the stationary actuator housing, wherein thepiston is rigidly connected and rotationally secured to the first plug,and wherein the cam member has at least two cam-surfaces inclined withrespect to the axial direction and configured for interacting with theradially protruding guiding members for inducing a controlled rotationof the piston and first plug upon motion of the piston and first plugfrom the retracted position to the protruding position, and back to theretracted position again. Thereby, the rotating mechanism may beimplemented in the linear actuator.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the cam member of the rotatingmechanism includes first and second annular sleeves mutually joined andaxially overlapping, wherein each of the first and second annularsleeves includes at least one cam-surface inclined with respect to theaxial direction, wherein the at least one radially protruding guidemember is configured for interacting with the at least one cam-surfaceof the first annular sleeve when the first plug moves from the retractedposition to the protruding position, and wherein the at least oneradially protruding guide member is configured for interacting with theat least one cam-surface of the second annular sleeve when the firstplug moves from the protruding position to the retracted position. Thisprovides a compact cam member having simplified manufacturing.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the rotating mechanism is arrangedsuch that 4-24 consecutive activation events, specifically, 6-12consecutive activation events, will result in the first plug performinga full turn. This enables increased ejection pressure due to reducedspray hole area.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the linear actuator is apneumatically or hydraulically operated single-acting cylinder-pistonactuator with a mechanical spring for biasing the piston towards a rearposition of the piston, wherein the cylinder-piston actuator furtherincludes a bearing arranged between the mechanical spring and the pistonfor simplifying relative rotation of the mechanical spring and piston.This provides simplified control of the actuator.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the second plug is movably arrangedrelative to the first plug in the axial direction and spring-loadedtowards a front side of the nozzle housing for providing improvedsealing contact with the first plug, in particular with the front walland/or the sleeve-shaped body of the first plug. This provides improvedsealing performance between first and second plugs.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the linear actuator is apneumatically or hydraulically operated cylinder-piston actuator,wherein the second plug extends into an actuator housing, and wherein amechanical spring of the second plug is located in the actuator housingand abuts a rear side of the second plug and front side of the piston.This provides a compact design.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the first set of spray holes providedon the front wall of the sleeve-shaped body are arranged in one or moreindividual front clusters of spray holes, wherein each hole of anindividual front cluster is located within a circular sector that havinga central angle of not more than 90 degrees, specifically with acircular sector that having a central angle of not more than 45 degrees.This provides maintained liquid ejection pressure with reduced supplypressure, or increased liquid ejection pressure with maintained supplypressure.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the front surface of first plug has asubstantially flat surface arranged in a plane perpendicular to theaxial direction, and the first set of spray holes is arranged in saidsubstantially flat surface. This provides a flush surface of thecleaning nozzle.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the first set of spray holes providedon the front wall of the sleeve-shaped body are arranged in twooppositely located individual front clusters of spray holes, whereineach front cluster includes about 5-15 holes. This provides maintainedliquid ejection pressure with reduced supply pressure, or increasedliquid ejection pressure with maintained supply pressure.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the first set of spray holes providedon the front wall of the sleeve-shaped body are arranged to ejectcleaning liquid with in an angular range of at least 0-30 degrees withrespect to the axial direction, and the second set of spray holesprovided in the sleeve-shaped body are arranged to eject cleaning liquidwith in an angular range of about 45-135 degrees with respect to theaxial direction. This enables a cleaning nozzle with very good coverageof the adjacent interior surface of the tank or pipe.

The disclosure also relates to an assembly comprising: a tank or a pipe;and a retractable cleaning nozzle as described above, wherein the nozzlehousing of the retractable cleaning nozzle is stationary mounted in ahole of a side wall of the pipe or the tank with a front side arrangedto face towards the interior of the tank or pipe.

In some example embodiments, that may be combined with any one or moreof the above-described embodiment, the retractable cleaning nozzlefurther comprises a rotating mechanism arranged to cause the first plugto become angularly displaced a predetermined angle, around its centrallongitudinal axis during each activation event, which involves movingthe first plug from the retracted position to the protruding position,and back to the retracted position again, the method comprises repeatingthe steps of controlling the linear actuator to move the first plug fromthe a retracted position to a protruding position, and subsequently tomove the first plug back from the protruding position to the retractedposition, for at least four times, specifically at least eight times,during a cleaning event, for providing at least one full turn of thefirst plug during a cleaning event.

Further features and advantages of the invention will become apparentwhen studying the appended claims and the following description. Theskilled person in the art realizes that different features of thepresent disclosure may be combined to create embodiments other thanthose explicitly described hereinabove and below, without departing fromthe scope of the present disclosure.

BRIEF DESCRIPTION OF DRAWINGS

The retractable cleaning nozzle and associated method of use accordingto the disclosure will be described in detail in the following, withreference to the attached drawings, in which

FIG. 1 shows schematically a perspective view of an example embodimentof the cleaning nozzle,

FIG. 2A-2D show a cross-section of an example embodiment of the cleaningnozzle in retracted state,

FIG. 3A-3B show a cross-section of the cleaning nozzle of FIGS. 2A-2D inprotruding state,

FIG. 4A-4C show various views of the first plug of the cleaning nozzleof FIGS. 2A-2D and 3A-3B,

FIG. 4D shows example ejection angles of a first plug,

FIG. 5A-5C show various views of the second plug of the cleaning nozzleof FIGS. 2A-2D and 3A-3B,

FIG. 6A-6C show various views of the cam member of the cleaning nozzleof FIGS. 2A-2D and 3A-3B,

FIG. 7A-7C show various views of the piston of the cleaning nozzle ofFIGS. 2A-2D and 3A-3B,

FIG. 8A-8B show cross-sections of a further example embodiment of thecleaning nozzle in retracted and protruding states,

FIG. 9A-9B show cross-sections of still a further example embodiment ofthe cleaning nozzle in retracted and protruding states,

FIG. 10A-10B show cross-sections of still another example embodiment ofthe cleaning nozzle in retracted and protruding states,

FIG. 11-12 show an assembly of the cleaning nozzle installed in a pipeor tank,

FIG. 13 shows an example of an asymmetric ejection pattern,

FIG. 14 shows a nozzle housing attached to a side wall,

FIG. 15-16 show main steps of some example methods of use of thecleaning nozzle.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Various aspects of the disclosure will hereinafter be described inconjunction with the appended drawings to illustrate and not to limitthe disclosure, wherein like designations denote like elements, andvariations of the described aspects are not restricted to thespecifically shown embodiments, but are applicable on other variationsof the disclosure.

FIG. 1 schematically shows a perspective view of a first exampleembodiment of the retractable cleaning nozzle 1 for spray cleaning aninterior surface of a pipe or a tank according to the disclosure. Asdiscussed more in detail below, the cleaning nozzle 1 has a first plug 2movably arranged in the axial direction AD between a retracted positionand a protruding position, and in FIG. 1 the first plug 2 is located inthe retracted position.

FIG. 2A shows a cross-section of the cleaning nozzle 1 of FIG. 1 withthe first plug in the retracted position, and FIGS. 2B, 2C and 2D aremagnifications of certain parts of the cleaning nozzle of FIG. 2A.

FIG. 3A shows a cross-section of the cleaning nozzle 1 of FIG. 1 withthe first plug in the protruding position, and FIG. 3B is amagnification of a portion of the cleaning nozzle of FIG. 3A.

With reference to FIGS. 1, 2A-2D and 3A-3B, the retractable cleaningnozzle 1 comprises a nozzle housing 3 configured to be stationarymounted in a hole of the side wall of the pipe or tank and having afront side 4 arranged to face towards the interior of the pipe or tankand a rear side 5 arranged to face away from the interior of the pipe ortank, an inlet port 6 configured for receiving cleaning fluid, and acylindrical interior bore 7 with a central axis 8 defining the axialdirection AD, wherein the interior bore 7 is open towards the front side4 of the nozzle housing 3.

The retractable cleaning nozzle 1 further comprises the first plug 2movably arranged in the axial direction AD within the bore 7 of thenozzle housing 3 between a retracted position and a protruding position.The first plug 2 has a sleeve-shaped body 9 with a front wall 10 closinga front portion of the sleeve-shaped body 9.

The front wall 10 of the sleeve-shaped body 9 includes a first set ofspray holes 11 configured to eject cleaning fluid substantially in theaxial direction AD. The sleeve-shaped body of the first plug furtherincludes a second set of spray holes 12 configured to eject cleaningfluid substantially in a radial direction RD perpendicular to the axialdirection AD.

Cleaning fluid located within the sleeve-shaped body 9 may thus onlyescape out from the interior of the sleeve-shaped body 9 either forwardsthrough the first set of spray holes 11, radially outwards through thesecond set of spray holes 12, or rearwards.

A front surface 13 of the first plug 2 is substantially flush with afront surface 14 of the nozzle housing 3 in the retracted position ofthe first plug 2, and a front portion of the first plug 2, including thefirst and second set of spay holes 11, 12, protrudes beyond the frontsurface 14 of the nozzle housing 3 in the protruding position of thefirst plug 2 for enabling spray cleaning of the interior surface of thepipe or tank.

The retractable cleaning nozzle 1 further comprises a second plug 15arranged within a space defined by the sleeve-shaped body 9 of the firstplug 2 and configured for closing a flow path from the inlet port to thefirst set of spray holes 11 of the first plug 2 when the first plug 2 islocated in the retracted position.

Thereby, a retractable cleaning nozzle 1 is provided that not only issubstantially flush over entire surface facing the interior surface ofthe tank or pipe for ensuring a high hygienic standard, the cleaningnozzle 1 is also able to eject cleaning fluid both substantially in theaxial direction AD and substantially in a radial direction RD forensuring improved cleaning efficiency.

In some example embodiments, the retractable cleaning nozzle furthercomprises a first sealing arrangement 16 for sealing the first plug 2 tothe nozzle housing 3, and a second sealing arrangement 17 for sealingthe second plug 15 to the first plug 2.

Specifically, in the example embodiment of FIGS. 2A-3B, the firstsealing arrangement 16 is configured for sealingly closing a passagebetween the first plug 2 and the nozzle housing 3, i.e. for sealing anannular space between the first plug 2 and the nozzle housing 3.

More in detail, the first sealing arrangement may be arranged forsealing an annular space between a radially outer surface of the firstplug 2 and a radially inner surface of the nozzle housing 3, inparticular between a radially outer surface of the first plug 2 and aradially inner surface of the interior bore 7 of the nozzle housing 3.Thereby, the cleaning fluid is prevented from leaking out from thecleaning nozzle through the annular space defined by the radially outersurface of the first plug 2 and the radially inner surface of theinterior bore 7 of the nozzle housing 3 when the first plug 2 is locatedin the retracted position.

In fact, in the example embodiment of the cleaning nozzle of FIGS. 1-3B,the first sealing arrangement 16 seals the first plug 2 to the nozzlehousing 3 in the retracted position of the first plug 2 only, becausethe first sealing arrangement 16 protrudes out from the nozzle housing 3when the first plug 2 is in the protruding position, i.e. is not incontact with the nozzle housing 3 when the first plug 2 is in theprotruding position.

Consequently, the portion of the sleeve-shaped body 9 having the secondset of spray holes 12 protrudes out and beyond the front surface 14 ofthe nozzle housing 3 in the protruding position of the first plug 2, andthe portion of the sleeve-shaped body 9 having the second set of spayholes 12 is located within the nozzle housing 3 and being sealed fromthe interior of the pipe or tank by means of the first sealingarrangement 16 in the retracted position of the first plug 2.

With reference to FIG. 3B, the first plug 2 may protrude a distance 72of about 5-100 mm from the front surface 14 of the housing 3 in theprotruding position, and be substantially flush with front surface 14 inthe retracted position.

FIG. 4A shows a perspective view of the first plug 2 in dismountedstate, i.e. detached from the nozzle housing 3, and FIG. 4B shows a rearview of the first plug 2 and FIG. 4C shows a cross-sectional view alongcut A-A of FIG. 4B.

With reference to FIGS. 1-4C, the first sealing arrangement 16 ismounted in an annular recess 18 in a radially outer surface of a frontportion 19 of the sleeve-shaped body 9 of the first plug 2. Thereby, thefirst sealing arrangement 16 is located relatively close to a frontsurface of the first plug 2, such that only a little fluid product mayenter the cleaning nozzle 1 when the first plug 2 is located in theretracted position.

The front surface 13 of first plug 2 has a substantially flat surfacearranged in a plane perpendicular to the axial direction AD, and thefirst set of spray holes 11 is arranged in said substantially flat frontsurface 13. This feature contributes to the flush front surface of thecleaning nozzle, thereby reducing the risk for contamination caused bypossible dirt or bacterial growth getting stuck in recess of thecleaning nozzle. Furthermore, by arranging the first set of spray holes11 in said substantially flat front surface 13, ejection of cleaningfluid in the axial direction AD, or at least substantially in the axialdirection AD, is enabled.

The substantially flat front surface 13 of first plug 2 in a planeperpendicular to the axial direction AD defines an angle of about 90degrees with a direction of elongation of the sleeve-shaped body 9 ofthe first plug 2. In other words, the front wall 10 of first plug 2together with the sleeve-shaped body 9 of the first plug 2 defines apiston-shaped hollow structure similar to those typically found in acombustion engine, where the piston crown corresponds to the front wall10 of the first plug 2, and the piston skirt corresponds to thesleeve-shaped body 9 of the first plug 2.

The annular recess 18 for holding the first sealing arrangement 16 islocated in the front portion 19 of the sleeve-shaped body 9, inparticular in a corner region of the first plug 2, at which the frontwall 10 and sleeve-shaped body 9 meet.

Consequently, the essentially flat front surface 13 of first plug 2extends primarily in the radial direction RD out to the first sealingarrangement 16.

In the example embodiment of FIGS. 2A-3B, the second sealing arrangement17 is configured for sealing an annular space between the second plug 15and the first plug 2. Specifically, the second sealing arrangement 17 isarranged for sealing an annular space located between a radially outersurface of a front flange 20 of the second plug 15 and a radially innersurface 33 of the front portion of the first plug 2.

Consequently, in this example embodiment of the cleaning nozzle, thesecond sealing arrangement 17 seals the second plug 15 to the first plug2 in the retracted position of the first plug 2 only. In the protrudingposition of the first plug 2, the second sealing arrangement 17 does notseal the second plug 15 to the first plug 2.

As a result, with reference to in particularly FIGS. 2A and 3B, thenozzle housing 3 has an inlet port 6 for receiving cleaning fluid andthe cleaning fluid is configured to flow from the inlet port 6 to thefirst and second set of spray holes 11, 12 via an annular passagedefined by the second sealing arrangement 17 and a radially innersurface of the sleeve-shaped portion 9 of the first plug 3, in theprotruding position of the first plug 2.

For the same reason, the cleaning fluid is configured to be stopped frombeing ejected first and second set of spray holes 11, 12 by means of thefirst and second sealing arrangements 16, 17, in the retracted positionof the first plug 2, in particular because the first sealing arrangement16 seals and closes the annular space between the radially outer surfaceof the first plug 2 and radially inner surface of the interior bore 7 ofthe nozzle housing 3, and the second sealing arrangement 17 seals andcloses the annular passage between the radially inner surface 33 of thesleeve-shaped portion 9 of the first plug 3 and the radially outersurface of the second plug 15.

Consequently, the retractable cleaning nozzle may be free from a closingmember located in front of the first set of spray holes 11, i.e. freefrom a member located in front of the first plug and configured forstopping the flow of cleaning liquid through the first set of sprayholes 11 when the first plug 2 shifts from protruding position toretracted position. As a result, the cleaning nozzle may be providedwith a very flat and flush front surface.

FIG. 5A shows a perspective view of the second plug 15 in dismountedstate, i.e. detached from the nozzle housing 3, and FIG. 5B shows a rearview of the second plug 2 and FIG. 5C shows a cross-sectional view alongcut A-A of FIG. 5B.

In this example embodiment of the cleaning nozzle, the second sealingarrangement 16 is mounted in an annular recess 21 in a radially outersurface of the flange 20 of the second plug 15.

When the first plug 2 is located in the retracted position, the firstset of spray holes 11 is closed by means of the second plug 15.Specifically, the second plug 15 may include a central cylindrical shaft24 having the radially outwards extending flange 20 at a front endthereof, and a forwards facing, preferably flat, surface 25 of theflange 20 abuts against a corresponding rearwards faced surface 26 ofthe front wall 10 of the first plug 2. Furthermore, the second sealingarrangement 17 ensures that cleaning fluid cannot reach the first set ofspray holes 11, and that fluid product within the tank or pipe cannotenter the cleaning nozzle 1.

An outer diameter D1 of the radially outwards extending flange 20 at thefront end of the second plug 15 may be at least 50% of an outer diameterD2 of the front surface 13 of the first plug 2 for enabling the firstset of spray holes 11 to be positioned over relatively large useful areaof the front surface 13 of the first plug 2.

Actuation of the first plug 2 between the retracted and protrudingposition may be accomplished in various ways. For example, theretractable cleaning nozzle 1 may include a linear actuator 27operatively connected to the moveable first plug 2 for controllingmovement of the first plug 2 between the retracted position andprotruding position.

The linear actuator 27 may for example be a pneumatic, hydraulic orelectric operated linear actuator.

In some example embodiments, the first plug 2 may include a centralcylindrical operating stem 28 extending in the axial direction andoperably connected to the linear actuator 27. The operating stem 28 mayfor example be connected to, or integrally formed with, the front wall10 of the first plug 2.

In such an arrangement, the second plug 15 may have a centralcylindrical hole 29 extending in the axial direction AD and configuredto receive the operating stem 28 of the first plug 2 and to enablerelative motion between the first and second plugs 2, 15.

In other words, the operating stem 28 of the first plug 2 may extendthrough the second plug 15 and be operatively connected to the linearactuator 27 on the rear side of the second plug 15. The second plug 15may thus be telescoped on the operating stem 28 of the first plug 2.

Furthermore, forwards motion of the operating stem 28 would result inforwards motion of the first plug 2, while the second plug 15 may remainmore or less stationary, thereby causing the cleaning nozzle to shiftfrom a passive state, in which the first plug 2 is in the retractedposition, to an active cleaning state, in which the first plug 2 is inthe protruding position.

In addition, in this example embodiment of the cleaning nozzle, a thirdsealing arrangement 22 may be mounted in an annular recess 23 in aradially inner surface of the flange 20 of the second plug 15 forsealing a passage between a radially inner surface of the second plug 15and a radially outer surface of the first plug 2 or the operating stem28 of first plug 2.

In some example embodiments, the first and second sealing arrangements16, 17 are located substantially in same radial plane when the firstplug 2 is in the retracted position. Being located substantially in sameradial plane means herein that the seals are displaced not more than 5mm from each other in axial direction AD. This enables reduced space inwhich a liquid product from the tank or pipe may enter into the cleaningnozzle in retracted position of the first plug 2, as well as efficientand reliable radial compression of said sealing arrangements between thebore 7 of the housing 3 and the operating stem 28 of the first plug 2.

Similarly, in some example embodiments, the first, second and thirdsealing arrangements may be located substantially in same radial plane,when the first plug is in retracted position. This enables furtherreduced space in which a liquid product from the tank or pipe may enterinto the cleaning nozzle in retracted position of the first plug 2, aswell as further improved radial compression of said sealing arrangementbetween the bore 7 of the housing 3 and the operating stem 28 of thefirst plug 2.

In some example embodiments, the cleaning nozzle 1 may include a fourthsealing arrangement 30 for sealing the first plug 2 to the nozzlehousing 3 in the protruding position of the first plug 2. In particular,the fourth sealing arrangement 30 is arranged for sealing an annularspace between the sleeve-shaped body 9 of first plug 2 and the radiallyinterior surface of the interior bore 7 the nozzle housing 3. Thereby,an ejection leakage flow of cleaning fluid between the first plug 2 andnozzle housing 3 in the protruding position of the first plug 2 may bereduced, thereby increasing the ejection flow out through the first andsecond sets of spray holes 11, 12.

In fact, the fourth sealing arrangement 30 may be seated in radiallyoutwards facing annular recess 31 located at a rear portion 32 of thesleeve-shaped body 9, and may be arranged for being in sliding contactwith the radially interior surface of the interior bore 7 during thedisplacement of the first plug 2 between the retracted and protrudingpositions, thereby reducing the risk that the fourth sealing arrangement30 accidentally and unintentionally escapes from the annular recess 31.

Consequently, the first sealing arrangement 16 is mounted in an annularrecess 18 in a radially outer surface of the front portion 19 of thesleeve-shaped body 9 of the first plug 2, and the fourth sealingarrangement 30 is mounted in an annular recess 31 in a radially outersurface of a rear portion 32 of the sleeve-shaped body 9 of the firstplug 2.

In some example embodiments, the second and fourth sealing arrangements17, 30, and in particular the second, third and fourth sealingarrangements 17, 22, 30, are located substantially in same radial planewhen the first plug 2 is in the protruding position. Being locatedsubstantially in same radial plane means herein that the seals aredisplaced not more than 5 mm from each other in axial direction AD. Thisenables efficient and reliable radial compression of said sealingarrangements between the bore 7 of the housing 3 and the operating stem28 of the first plug 2 in the protruding position.

The various sealing arrangements describes above may be implementedusing various types of annular seals, such as O-rings or the like.Hence, the first sealing arrangement may be implemented as a sealingring, in particular an O-ring. The second sealing arrangement may alsobe implemented a sealing ring, in particular an O-ring. The thirdsealing arrangement may be implemented as a sealing ring, in particularan O-ring. Also the fourth sealing arrangement may be implemented as asealing ring, in particular an O-ring.

The cleaning nozzle is generally made of metal material, such asstainless steel or similar type of hygienic material. Consequently, eachof the nozzle housing and the first and second plugs may be made ofstainless steel or the like.

As schematically illustrated in FIGS. 2A and 3A, the linear actuator 27may be implemented as a pneumatic cylinder having a stationary actuatorhousing 34 and a driving member in form of a piston 36 operativelyconnected with a central actuating member 35. The piston 36 beingoperable by supplying pressurized air into a pressure chamber 58 of thecylinder via an air supply connector 59. The stationary actuator 34housing may be rigidly attached to the stationary nozzle housing 3, andthe actuating member 35 may be operatively connected with the operatingstem 28 of the first plug 2 for controlling movement of the moveablefirst plug 2 between the retracted position and protruding position.

The linear actuator 27 may however alternatively be implemented as ahydraulic cylinder, or an electric linear actuator having for example adriving member in form of a threaded nut engaged with a linearlymoveable threaded rod acting as actuating member.

If the first and/or second set of spray holes 11, 12 of the first plug 2are substantially evenly distributed and a sufficiently large ejectionpressure of the cleaning liquid is reached, the cleaning nozzle maygenerate a satisfactory cleaning performance of the interior surface ofthe tank or pipe without a rotating mechanism arranged to cause thefirst plug to rotate.

However, in certain situations, for example when the fluid pressure ofthe supplied cleaning fluid is relatively low for same reason, theejection pressure of the cleaning liquid may be too low when there are arelatively large number of spray holes. Such a situation may for exampleoccur when the cleaning liquid pump used for supplying the cleaningliquid to the cleaning nozzle 1 has a relatively small capacity forenabling a more cost-efficient and energy-efficient design of thecleaning system.

Consequently, for accomplishing a relatively long operating distance ofthe cleaning nozzle while avoiding use of a large, costly and powerfulpump, the cleaning nozzle 1 may be provided with a relatively smallnumber of spray holes. Thereby, the ejection pressure of the cleaningliquid at the spray holes may be upheld despite use of a smaller pumpcapacity. Furthermore, for accomplishing a satisfactory cleaning resultdespite use of fewer spray holes, the retractable cleaning nozzle mayinclude a rotating mechanism for rotating the first plug during use ofthe cleaning nozzle 1. Thereby, satisfactory cleaning performance isaccomplished in combination with a more cost-efficient andenergy-efficient pump design.

In other words, according to some example embodiments, the retractablecleaning nozzle 1 may include a rotating mechanism 37 arranged to causethe first plug 2 to become angularly displaced a predetermined angle,such as for example in the range of 5-175 degrees, specifically in therange of 20-110 degrees, around its central longitudinal axis duringeach activation event, which involves moving the first plug 2 from theretracted position to the protruding position, and back to the retractedposition again.

With reference to FIGS. 2A, 2C, 3A, 6A-C and 7A-C, according to someexample embodiments, the rotating mechanism 37 includes at least oneradially protruding guide member 38 rotationally connected with thefirst plug 2 and a cam member 39 rotationally connected with thestationary actuator housing 34, wherein the cam member 39 may have atleast one cam-surface 40 inclined with respect to the axial direction ADand configured for interacting with the at least one radially protrudingguiding member 38 for inducing a controlled rotation of the first plug 2upon motion of the first plug 2 from the retracted position to theprotruding position, and back to the retracted position again.

In the example embodiment of FIGS. 2A, 2C, 3A, 6A-C and 7A-C, therotating mechanism 37 includes four radially protruding guide members 38distributed around the circumference of a sleeve member 41 associatedwith the piston 36, which is rotationally connected with the first plug2 via the actuating member 25 and operating stem 28.

In some example embodiments, the rotating mechanism 37 may be arrangedto cause the first plug 2 to become angularly displaced a firstpredetermined angle around its central longitudinal axis during motionof the first plug 2 from the retracted position to the protrudingposition. The rotating mechanism 37 is further arranged to cause thefirst plug 2 to become angularly displaced a second predetermined anglearound its central longitudinal axis during motion of the first plug 2from the protruding position to the retracted position.

Hence, during each activation event, which involves moving the firstplug 2 from the retracted position to the protruding position, and backto the retracted position again, the piston 36 and thereto connectedfirst plug 2 will perform two individual rotational movements, one whenthe piston 36 moves forward and the first plug 3 moves from theretracted position to the protruding position, and one when the piston36 moves rearwards and the first plug 2 moves from the protrudingposition to the retracted position.

This two-step motion of the piston 36 is caused by design of the sleevemember 41 of the stationary actuator housing 34, which design involvestwo cam surfaces for each guide member 38 and activation event. Indetail, a first cam surface 40 interacts with the protruding guidemember 38 during the piston forwards motion, and a further cam surface43 interacts with the protruding guide member 38 during the pistonrearwards motion.

The cam member 39 of FIGS. 6A-C has eight cam-surfaces 40 distributedaround the circumference of the cam member 39 for providing the firstrotational step, and eight further cam-surfaces 43 distributed aroundthe circumference of the cam member 39 for providing the secondrotational step. Hence, the cleaning nozzle according to this exampleembodiment requires eight activation events for performing a full 360degree rotation of the first plug 2. However, the number of cam-surfacesmay of course be varied according to the specific circumstances andneeds.

Furthermore, this two-step design of the cam member 39 is optional andthe cam member 39 may be implemented using a single cam surface for eachactivation event.

The radially protruding guide member 38 may for example be a radiallyprotruding pin, slider, or roller. As depicted in FIG. 2C, the guidemember 38 may even be roller having a roller bearing 44 for furtherreduced frictional losses.

According to some example embodiments, the rotating mechanism 37 mayinclude a set of at least two radially protruding guide members 38rotationally connected with a piston 36 of the pneumatic linear actuator27, and a cam member 39 rotationally secured to the stationary actuatorhousing 34, wherein the piston 36 is rigidly connected and rotationallysecured to the first plug 2, and wherein the cam member 39 has at leasttwo cam-surfaces inclined with respect to the axial direction andconfigured for interacting with the radially protruding guiding members38 for inducing a controlled rotation of the piston 36 and first plug 2upon axial motion of the piston 36 and first plug 2 from the retractedposition to the protruding position, and back to the retracted positionagain.

With reference to FIGS. 6A-6C, the cam member 39 of the rotatingmechanism 37 may according to some example embodiments include first andsecond annular sleeves 39 a, 39 b mutually joined and axiallyoverlapping, wherein each of the first and second annular sleeves 39 a,39 b includes at least one cam-surface 40, 43 inclined with respect tothe axial direction AD, wherein the at least one radially protrudingguide member 38 is configured for interacting with the at least onecam-surface 40 of the first annular sleeve 39 a when the first plug 2moves from the retracted position to the protruding position, andwherein the at least one radially protruding guide member 38 isconfigured for interacting with the at least one cam-surface 43 of thesecond annular sleeve 39 b when the first plug 2 moves from theprotruding position to the retracted position.

The exact number of radially protruding guide members 38 may depend onthe specific circumstances, and may for example be in the range of 2-16individual guide members 38.

Similarly, the rotating mechanism may, depending on the circumstances,be arranged to perform a suitably large angular rotations for eachactivation event. For example, rotating mechanism may be arranged suchthat 4-24 consecutive activation events, specifically, 6-12 consecutiveactivation events, will result in the first plug performing a full turn,i.e. rotating at least 360 degrees around the central axis 8.

The cleaning nozzle 1 is not limited to the example embodiment of FIGS.2A, 2C, 3A, 6A-C and 7A-C and various changes may be made to thecleaning nozzle 1 and/or rotating mechanism 37. For example, withrespect to the rotating mechanism, the cam member 39 may be rotationallyconnected with the piston 36 and/or first plug 2, and the radiallyprotruding guide members 38 may be rotationally secured to thestationary actuator housing 34. Furthermore, the rotating mechanism 37including the radially protruding guide members 38 and the cam member 39may even be implemented in the nozzle housing 3 instead, therebyenabling use of a more conventional linear actuator.

The linear actuator 27 may have a housing 34 for surrounding the pistonand rotating mechanism 37, wherein the housing 34 includes a rear wall46, a front wall 42 and a cylindrical wall 47 extending between thefront and rear walls 42, 46.

In the example embodiment of FIGS. 2A and 3A, the actuating member 35extends rearwards through the rear wall 46 of the linear actuator 27 forenabling for example position detection of the linear actuator 27 usinga suitable sensor device. However, this is optional and the actuatingmember 35 may alternatively not extend through the rear wall 46, whichmay then be closed instead.

Depending on the overall design of the retractable cleaning nozzle 1, aspacer 57 may be provided between the linear actuator 27 and nozzlehousing 3. In the example embodiment of FIGS. 2A and 3A, the spacer 57is integrated in the front wall 42 of the actuator 27.

The linear actuator 37 is for example a pneumatically or hydraulicallyoperated single-acting cylinder-piston actuator with a mechanical returnspring 45 for biasing the piston 36 towards a rear position of thepiston 36. The return spring 45 may thus be installed between a frontwall 42 of the actuator housing 34 and front side of the piston 36.

Furthermore, as illustrated in FIG. 2D, the cylinder-piston actuator 27may additionally include a roller bearing 70 arranged between themechanical spring 45 of the first plug 2 and the piston 36 forsimplifying relative rotation of the mechanical spring 45 and piston 36,if the linear actuator 27 has a rotating mechanism 37 integratedtherein.

With reference to FIGS. 1 and 4B, the first set of spray holes 11provided in the front wall 10 of the sleeve-shaped body 9 may bearranged in one, two, three, four or more individual front clusters 48of spray holes 11, wherein each spray hole 11 of an individual frontcluster 48 may be located within a circular sector 49 that having acentral angle 50 of not more than 90 degrees, specifically with acircular sector that having a central angle of not more than 45 degrees.

For example, the first set of spray holes 11 provided in the front wall10 of the sleeve-shaped body 9 may be arranged in two individual andoppositely located front clusters 48 of spray holes 11, wherein eachspray hole 11 of an individual front cluster 48 may be located within acircular sector 49 that having a central angle 50 of not more than 45degrees. According to some example embodiments, each front cluster 48includes about 5-15 spray holes.

Thereby, the resulting ejection pattern of the first set of spray holes11 may be relatively narrow in a first radial direction RD1 andrelatively wide in a second radial direction RD2 located substantiallyperpendicular to the first radial direction, as schematicallyillustrated in FIG. 13 . This type of ejection pattern may beparticularly suitable for a rotatable first plug 2 because therelatively narrow ejection pattern enables stronger ejection pressurewithout requiring higher pump capacity, and a satisfactory cleaningperformance is still obtained due to the rotatable first plug 2, i.e.rotatable ejection pattern.

In other words, the non-evenly distributed cluster-shaped first set ofspray holes 11 enables either maintained cleaning liquid ejectionpressure with reduced pump supply pressure, or increased liquid ejectionpressure with maintained pump supply pressure.

FIG. 4D schematically shows an example embodiment of a first plug 2having a first set of spray holes 11 and a second set of spray holes 12,wherein the first set of spray holes 11 provided in the front wall 10 ofthe sleeve-shaped body 9 are arranged to eject cleaning liquid with inan angular range of at least 0-30 degrees with respect to the axialdirection AD, as depicted by first angle 51. Furthermore, the second setof spray holes 12 provided in the sleeve-shaped body 9 are arranged toeject cleaning liquid with in an angular range of about 45-135 degreeswith respect to the axial direction AD, as depicted by the second angle52 and the third angle 53.

For increasing likelihood that the ejection pressure of the cleaningliquid at the first and second set of spray holes is sufficientlystrong, a flow area of the inlet port 6 may be selected to be largerthan an accumulated flow area of the first and second sets spray holes11, 12 taken together. Specifically, the flow area of the inlet port 6may be selected to be at least two times larger than the accumulatedflow area of the first and second sets spray holes 11, 12.

Hence, for example, in case the flow area of the inlet port 6 is about400 mm2, the accumulated flow area of the first and second sets sprayholes 11, 12 taken together may be selected to be not more than 400 mm2,specifically less than 200 mm2. The flow area of the inlet port and/or aspray hole corresponds to the flow area, i.e. effective flow area, ofthe pipe port or spray opening.

With reference to FIGS. 2A and 3A, the second plug 15 may be movablyarranged relative to the first plug 2 in the axial direction AD andspring-loaded towards a front side 14 of the nozzle housing 3 forproviding improved sealing contact between the first and second plugs 2,15 in the retracted position of the first plug 2. The spring-loadedsecond plug 15 ensures particularly good sealing performance between thefront flange 20 of the second plug 15 and the front wall 10 and/or thesleeve-shaped body 9 of the first plug 2.

The spring-loaded second plug 15 may be accomplished in a variety ofways. For example, as schematically illustrated in FIGS. 2A and 3A, thelinear actuator 27 may be a pneumatically or hydraulically operatedcylinder-piston actuator 27, wherein the second plug 15 extends into theactuator housing 34 via a connection arrangement 55, and wherein amechanical spring 54 of the second plug 15 is located in the actuatorhousing 34 and abuts a rear side of the second plug 15, specifically arear side of a member of the connection arrangement 55, and front sideof the piston 36.

Thereby, the second plug 15 is always urged forwards against a valveseat on the rear side of the first plug 2, in the retracted position ofthe first plug 2. In the protruding position of the first plug 2 thesecond plug 15 must have some kind of forwards motion limitingarrangement for avoiding that the second sealing arrangement remains insealing contact with the first plug 2, because this would preventcleaning liquid from reaching the first set of spray holes. In theexample embodiment of illustrated in FIG. 3A, said forwards motionlimiting arrangement 56 is implemented by means of flange member of theconnection arrangement 55 of the second plug 15 that is configured toabut a rear side 5 of the nozzle housing 3 when the first plug 2 is inthe protruding position.

As illustrated in FIG. 2D, the cylinder-piston actuator 27 mayadditionally include a roller bearing 71 arranged between the mechanicalspring 54 of the second plug 15 and the piston 36 for simplifyingrelative rotation of the mechanical spring 54 and piston 36, if thelinear actuator 27 has a rotating mechanism 37 integrated therein.

Many alternative embodiments of the retractable cleaning nozzle arepossible within the scope of the appended claims. For example, a furtherexample embodiment of the cleaning nozzle 1 is schematically illustratedin retracted state in FIG. 8A and protruding state in FIG. 8B. Thisexample embodiment of the cleaning nozzle corresponds largely to thepreviously described example embodiment, but without the previouslydescribed rotating mechanism 37. However, a rotating mechanism 37 may beimplemented in the cleaning nozzle 1 of FIGS. 8A-B if desired. Thevarious part and functionality is not repeated here and reference isinstead made to description above and FIGS. 1-7C for detaileddescription of the parts.

Still a further example embodiment of the cleaning nozzle 1 isschematically illustrated in retracted state in FIG. 9A and protrudingstate in FIG. 9B. This example embodiment of the cleaning nozzlecorresponds largely to the previously described example embodiment, butwith a stationary mounted second plug 15. This type of simplifiedmounting of the second plug 15 provides a more cost-efficient designthat may be suitable in some implementations. This cleaning nozzle alsolacks the previously described rotating mechanism 37. However, arotating mechanism 37 may be implemented in the cleaning nozzle 1 ofFIGS. 9A-B if desired. The various part and functionality is notrepeated here and reference is instead made to description above andFIGS. 1-7C for detailed description of the parts.

Still a further example embodiment of the cleaning nozzle 1 isschematically illustrated in retracted state in FIG. 10A and protrudingstate in FIG. 10B. This example embodiment of the cleaning nozzlecorresponds largely to the previously described example embodiment, butwith the spring 54 of the second plug 15, as well as the forwards motionlimiting arrangement 56, installed within the nozzle housing 3 instead.This enables use a simplified linear actuator design. This cleaningnozzle also lacks the previously described rotating mechanism 37.However, a rotating mechanism 37 may be implemented in the cleaningnozzle 1 of FIGS. 10A-B if desired. The various part and functionalityis not repeated here and reference is instead made to description aboveand FIGS. 1-7C for detailed description of the parts.

With reference to FIGS. 11 and 12 , the disclosure also relates to anassembly comprising a tank or a pipe, and a retractable cleaning nozzleas described above. For example, FIG. 11 shows a portion of pipe 60having a plurality of retractable cleaning nozzles installed in a wallof the pipe at regularly spaced apart positions from each other. Thecleaning nozzles 1 may thus be used for cleaning the interior surface 61of the pipe 60. The pipe may for example have a diameter 62 in the rangeof about 0.1-3 metres, specifically about 0.3-1.5 metres. Neighbouringcleaning nozzles may for example be positioned with a distance 63 ofabout 0.5-3 metres from each other. Each cleaning nozzle 1 receivescleaning fluid via a supply pipe 64 connected to the cleaning nozzle 1.

FIG. 12 schematically shows a tank 65 fora working product, such as afluid, having an inlet opening, an outlet opening, and a retractablecleaning nozzle 1 installed in wall of the tank 65. The cleaning nozzles1 may thus be used for cleaning the interior surface 61 of the tank 65.The tank may for example have a diameter 62 in the range of about 1-3metres, and the cleaning nozzle may thus be configured to have anoperating range of at least 3 metres. The cleaning nozzle may beconfigured to have a relatively large ejection angle 66, i.e. at least180 degrees, for enabling efficient and reliable cleaning of theinterior surface 61 of the tank 65.

The first set of spray holes 11 may be configured to provide anasymmetric ejection pattern 67, as schematically illustrated in FIG. 13, which shows an example of a cross-section of an ejection pattern 67 ofthe first set of spray holes 11 of a cleaning nozzle 1 for a certainrotational position. However, due to the rotational character of thecleaning nozzle according to certain embodiments, the cleaning nozzle 1will nevertheless, despite the asymmetric ejection pattern, provide afull coverage of the adjacent interior surface of the tank 65 or pipe60.

The second set of spray holes 12 arranged within the sleeve-shaped body9 may also be arranged in asymmetrically, i.e. having an asymmetricejection pattern that requires a rotating mechanism 37 for providingfull coverage of the adjacent interior surface of the tank or pipe, andthereby further contributing to improved cost-efficiency andenergy-efficient design of the cleaning nozzle 1.

FIG. 14 schematically shows only the nozzle housing 3 of the retractablecleaning nozzle 1 stationary mounted in a hole of a side wall 68 of thepipe 60 or the tank 65. The nozzle housing 3 may for example have amounting flange 69 that is welded to the side wall 68 at the opening.The front side 4 of the nozzle housing is arranged to face towards theinterior of the tank or pipe, and the front surface 4 of the housing 3is preferably arranged substantially flush with the interior surface 61of the side wall 68 of the tank 65 or pipe 60.

The disclosure also relates to a method for spray cleaning an interiorsurface of a pipe 60 or a tank 65 using a retractable cleaning nozzle 1,which has a nozzle housing 3 stationary mounted in a hole of a side wall68 of the pipe 60 or tank 65. The nozzle housing 3 may have a front side4 facing towards the interior of the pipe 60 or tank 65 and a rear side5 facing away from the interior of the pipe or tank. The nozzle housing3 may further have an inlet port 6 for receiving a cleaning liquid, acylindrical interior bore 7 with a central axis 8 defining an axialdirection AD, a first plug 2 movably arranged in the axial directionwithin the bore 7, and a second plug 15.

FIG. 15 schematically shows the main steps. Specifically, the methodcomprises a first step S1 of controlling a linear actuator 27operatively connected to the moveable first plug 2 for moving the firstplug 2 from the a retracted position to a protruding position, in whicha front portion of the first plug 2, including a first and a second setof spay holes 11, 12, protrudes into the tank or pipe, therebyinitiating ejection of cleaning fluid via the first set of spray holes11 of the first plug 2 substantially in the axial direction AD, andinitiating ejection of cleaning fluid via the second set of spray holes12 of the first plug 2 substantially in a radial direction RDperpendicular to the axial direction AD.

The method comprises a second step S2 of controlling the linear actuator27 for moving the first plug 2 from the protruding position to theretracted position, in which a front surface 13 of the first plug 2 issubstantially flush with a front surface 14 of the nozzle housing 3, andin which the second plug 15 closes the flow path from the inlet port 6to the first set of spray holes 11 of the first plug 2.

According to some example embodiments, the retractable cleaning nozzle 1may further comprise a rotating mechanism 37 arranged to cause the firstplug 2 to become angularly displaced a predetermined angle, around itscentral longitudinal axis during each activation event, which involvesmoving the first plug 2 from the retracted position to the protrudingposition, and back to the retracted position again. The above-describedmethod for spray cleaning an interior surface of a pipe 60 or a tank 65using a retractable cleaning nozzle 1 may in such case involve repeatingsaid first and second steps S1, S2 of controlling the linear actuator tomove the first plug from the a retracted position to a protrudingposition, and subsequently to move the first plug back from theprotruding position to the retracted position, at least four times, asschematically illustrated by the method steps of FIG. 16 , during acleaning event, for providing at least one full turn of the first plug 2during a cleaning event.

It will be appreciated that the above description is merely exemplary innature and is not intended to limit the present disclosure, itsapplication or uses. While specific examples have been described in thespecification and illustrated in the drawings, it will be understood bythose of ordinary skill in the art that various changes may be made andequivalents may be substituted for elements thereof without departingfrom the scope of the present disclosure as defined in the claims.Furthermore, modifications may be made to adapt a particular situationor material to the teachings of the present disclosure without departingfrom the essential scope thereof.

Therefore, it is intended that the present disclosure not be limited tothe particular examples illustrated by the drawings and described in thespecification as the best mode presently contemplated for carrying outthe teachings of the present disclosure, but that the scope of thepresent disclosure will include any embodiments falling within theforegoing description and the appended claims. Reference signs mentionedin the claims should not be seen as limiting the extent of the matterprotected by the claims, and their sole function is to make claimseasier to understand.

REFERENCE SIGNS 1. Retractable cleaning nozzle 2. First plug 3. Nozzlehousing 4. Front side of housing 5. Rear side of housing 6. Inlet port7. Interior bore of housing 8. Central axis of bore 9. Sleeve-shapedbody 10. Front wall 11. First set of spray holes 12. Second set of sprayholes 13. Front surface of first plug 14. Front surface of housing 15.Second plug 16. First sealing arrangement 17. Second sealing arrangement18. Annular recess for holding first sealing arrangement 19. Frontportion of the sleeve- shaped body 20. Flange of second plug 21. Annularrecess for holding second sealing arrangement 22. Third sealingarrangement 23. Annular recess for holding third sealing arrangement 24.Central shaft of second plug 25. Forwards facing surface of second plug26. Rearwards facing surface of front wall 27. Linear actuator 28.Operating stem of first plug 29. Central hole of second plug 30. Fourthsealing arrangement 31. Annular recess for holding fourth sealingarrangement 32. Rear portion of the sleeve- shaped body 33. Innersurface of first plug 34. Actuator housing 35. Actuating member 36.Piston 37. Rotating mechanism 38. Radially protruding guide member 39.Cam member 40. Cam surface 41. Sleeve member of piston 42. Front wall ofactuator housing 43. Further cam surface 44. Roller bearing of guidemember 45. Spring of first plug 46. Rear wall of actuator housing 47.Cylindrical wall of actuator housing 48. Individual front cluster 49.Circular sector 50. Central angle 51. First angle 52. Second angle 53.Third angle 54. Spring of second plug 55. Connection arrangement ofsecond plug 56. Forwards motion limiting arrangement 57. Spacer 58.Pressure chamber 59. Air supply connector 60. Pipe 61. Interior surface62. Diameter of pipe 63. Distance between nozzles 64. Supply pipe 65.Tank 66. Ejection angle 67. Ejection pattern 68. Side wall 69. Mountingflange 70. Roller bearing of spring of first plug 71. Roller bearing ofspring of second plug 72. Protruding distance

1. A retractable cleaning nozzle for spray cleaning an interior surfaceof a pipe or a tank, the cleaning nozzle comprising: a nozzle housingconfigured to be stationary mounted in a hole of the side wall of thepipe or tank and having a front side arranged to face towards theinterior of the pipe or tank and a rear side arranged to face away fromthe interior of the pipe or tank, an inlet port configured for receivinga cleaning fluid, and a cylindrical interior bore with a central axisdefining an axial direction, wherein the interior bore is open towardsthe front side of the nozzle housing; a first plug movably arranged inthe axial direction within the bore of the nozzle housing between aretracted position and a protruding position, wherein the first plug hasa sleeve-shaped body with a front wall closing a front portion of thesleeve-shaped body, wherein the front wall of the sleeve-shaped bodyincludes a first set of spray holes configured to eject cleaning fluidsubstantially in the axial direction, wherein the sleeve-shaped body ofthe first plug includes a second set of spray holes configured to ejectcleaning fluid substantially in a radial direction perpendicular to theaxial direction, wherein a front surface of the first plug issubstantially flush with a front surface of the nozzle housing in theretracted position of the first plug, and wherein a front portion of thefirst plug, including the first and second set of spay holes, protrudesbeyond the front surface of the nozzle housing in the protrudingposition of the first plug for enabling spray cleaning of the interiorsurface of the pipe or tank; and a second plug arranged within a spacedefined by the sleeve-shaped body of the first plug and configured forclosing a flow path from the inlet port to the first set of holes of thefirst plug when the first plug is located in the retracted position. 2.The retractable cleaning nozzle according to claim 1, furthercomprising: a first sealing arrangement for sealing the first plug tothe nozzle housing; and a second sealing arrangement for sealing thesecond plug to the first plug.
 3. The retractable cleaning nozzleaccording to claim 1, wherein the first plug further has a centralcylindrical operating stem extending in the axial direction, and whereinthe second plug has a central cylindrical hole extending in the axialdirection and configured to receive the operating stem of the firstplug.
 4. The retractable cleaning nozzle according to claim 1, furthercomprising a linear actuator operatively connected to the moveable firstplug for controlling movement of the first plug between the retractedposition and the protruding position.
 5. The retractable cleaning nozzleaccording to claim 1, further comprising a rotating mechanism arrangedto cause the first plug to become angularly displaced a predeterminedangle around a central longitudinal axis thereof during each activationevent, which involves moving the first plug from the retracted positionto the protruding position, and back to the retracted position again. 6.The retractable cleaning nozzle according to claim 5, wherein therotating mechanism includes: at least one radially protruding guidemember rotationally connected with the first plug and a cam memberrotationally connected with the stationary nozzle housing or an actuatorhousing, or at least one radially protruding guide member rotationallyconnected with the stationary nozzle housing or the actuator housing anda cam member rotationally connected with the first plug, wherein the cammember has at least one cam-surface inclined with respect to the axialdirection and configured for interacting with the at least one radiallyprotruding guiding member for inducing a controlled rotation of thefirst plug upon motion of the first plug from the retracted position tothe protruding position, and back to the retracted position again. 7.The retractable cleaning nozzle according to claim 6, wherein the cammember of the rotating mechanism includes first and second annularsleeves mutually joined and axially overlapping, wherein each of thefirst and second annular sleeves includes at least one cam-surfaceinclined with respect to the axial direction, wherein the at least oneradially protruding guide member is configured for interacting with atleast one cam-surface of the first annular sleeve when the first plugmoves from the retracted position to the protruding position, andwherein the at least one radially protruding guide member is configuredfor interacting with at least one cam-surface of the second annularsleeve when the first plug moves from the protruding position to theretracted position.
 8. The retractable cleaning nozzle according toclaim 1, wherein the second plug is movably arranged relative to thefirst plug in the axial direction and spring-loaded towards a front sideof the nozzle housing for providing improved sealing contact with thefirst plug.
 9. The retractable cleaning nozzle according to claim 4,wherein the linear actuator is a pneumatically or hydraulically operatedcylinder-piston actuator, wherein the second plug extends into anactuator housing, and wherein a mechanical spring of the second plug islocated in the actuator housing and abuts a rear side of the second plugand front side of the piston.
 10. The retractable cleaning nozzleaccording to claim 1, wherein the first set of spray holes provided onthe front wall of the sleeve-shaped body are arranged in one or moreindividual front clusters of spray holes, wherein each spray hole of anindividual front cluster is located within a circular sector having acentral angle of not more than 90 degrees.
 11. The retractable cleaningnozzle according to claim 1, wherein the front surface of the first plughas a substantially flat surface arranged in a plane perpendicular tothe axial direction, and the first set of spray holes is arranged insaid substantially flat surface.
 12. The retractable cleaning nozzleaccording to claim 1, wherein the first set of spray holes provided onthe front wall of the sleeve-shaped body are arranged to eject cleaningliquid within an angular range of at least 0-30 degrees with respect tothe axial direction, and the second set of spray holes provided in thesleeve-shaped body are arranged to eject cleaning liquid within anangular range of about 45-135 degrees with respect to the axialdirection.
 13. An assembly comprising: a tank or a pipe; and theretractable cleaning nozzle according to claim 1, wherein the nozzlehousing of the retractable cleaning nozzle is stationary mounted in ahole of a side wall of the pipe or the tank with a front side arrangedto face towards the interior of the tank or pipe.
 14. A method for spraycleaning an interior surface of a pipe or a tank using a retractablecleaning nozzle, the retractable cleaning nozzle having a nozzle housingstationary mounted in a hole of a side wall of the pipe or tank, whereinthe nozzle housing has a front side facing towards the interior of thepipe or tank and a rear side facing away from the interior of the pipeor tank, wherein the nozzle housing further has an inlet port forreceiving a cleaning liquid, a cylindrical interior bore with a centralaxis defining an axial direction, a first plug movably arranged in theaxial direction within the bore and a second plug, the methodcomprising: controlling a linear actuator operatively connected to themoveable first plug for moving the first plug from the a retractedposition to a protruding position, in which a front portion of the firstplug, including a first and a second set of spay holes, protrudes intothe tank or pipe, thereby initiating ejection of cleaning fluid via thefirst set of spray holes of the first plug substantially in the axialdirection, and initiating ejection of cleaning fluid via the second setof spray holes of the first plug substantially in a radial directionperpendicular to the axial direction; and controlling the linearactuator for moving the first plug from the protruding position to theretracted position, in which a front surface of the first plug issubstantially flush with a front surface of the nozzle housing, and inwhich the second plug closes the flow path from the inlet port to thefirst set of spray holes of the first plug.
 15. The method according toclaim 14, wherein the retractable cleaning nozzle further comprises arotating mechanism arranged to cause the first plug to become angularlydisplaced a predetermined angle, around a central longitudinal axisthereof during each activation event, which involves moving the firstplug from the retracted position to the protruding position, and back tothe retracted position again, the method comprising repeating the stepsof controlling the linear actuator to move the first plug from the aretracted position to a protruding position, and subsequently to movethe first plug back from the protruding position to the retractedposition, for at least four times, during a cleaning event, forproviding at least one full turn of the first plug during a cleaningevent.
 16. The retractable cleaning nozzle according to claim 1, furthercomprising: a first sealing arrangement for sealing an annular spacebetween the first plug and the nozzle housing; and a second sealingarrangement for sealing an annular space between the second plug and thefirst plug.
 17. The retractable cleaning nozzle according to claim 1,further comprising a rotating mechanism arranged to cause the first plugto become angularly displaced a predetermined angle in the range of5-175 degrees around a central longitudinal axis thereof during eachactivation event, which involves moving the first plug from theretracted position to the protruding position, and back to the retractedposition again.
 18. The retractable cleaning nozzle according to claim1, further comprising a rotating mechanism arranged to cause the firstplug to become angularly displaced a predetermined angle in the range of20-110 degrees around a central longitudinal axis thereof during eachactivation event, which involves moving the first plug from theretracted position to the protruding position, and back to the retractedposition again.
 19. The retractable cleaning nozzle according to claim1, wherein the second plug is movably arranged relative to the firstplug in the axial direction and spring-loaded towards a front side ofthe nozzle housing for providing improved sealing contact with the frontwall and/or the sleeve-shaped body of the first plug.
 20. Theretractable cleaning nozzle according to claim 1, wherein the first setof spray holes provided on the front wall of the sleeve-shaped body arearranged in one or more individual front clusters of spray holes,wherein each spray hole of an individual front cluster is located withina circular sector having a central angle of not more than 45 degrees.